1. Field of the Invention
The present invention relates to computerized devices that automatically record information concerning the moves that human players make while playing board games. In particular, the present invention comprises a method for further processing such move information in order to create a fully accurate and complete game record.
2. Objectives of the Present Invention
It is well known that a good way for a player to improve his play in a board game such as chess or checkers (draughts) is to record personal games for later analysis. Manual recording of games, however, can be distracting to the player and his opponent, and is prone to errors that can make the game record difficult or impossible to interpret at a later time. For this reason, board game devices have been created that attempt to automatically recognize and record the moves of a game while it is being played. Many types of such devices have been created utilizing a wide range of technologies. To accomplish their task, all such devices must be capable of detecting the presence or absence of a playing piece on any possible board location. Some of the devices, however, are further capable of determining the identity of the particular playing piece at each location, and are hereinafter referred to as piece-identity devices. The aforementioned devices that cannot also determine the identity of each playing piece are hereinafter referred to as presence-only devices.
When prior art devices have been used to record games, such as chess, between two human players, it has primarily been for the purpose of displaying the game moves, as they occur, for the benefit of an audience. This use requires that the moves be accurately detected in real time with no chance for ambiguity. Therefore, piece-identity devices are required for that purpose. Such piece-identity devices can also be used to record casual games for later analysis. However, piece-identity devices are presently complex and expensive and may require manual input from the players and/or connection to external computers and external power outlets. Casual players who simply wish to record games for later personal use are not well served by such devices.
Presence-only devices, in contrast, often have the advantage of lower cost and the convenience of portability that derives from battery-powered operation. Presence-only devices, however, can have difficulty in recognizing exactly which move was made in certain ambiguous cases. A particular example of ambiguity can occur in the game of chess during capture moves. In the game of chess, a playing piece may have the option to choose which of multiple opposing pieces it will capture. A presence-only recording device can detect that the capturing piece has left its original square, but it may not detect any other change in the board position. This can happen when the captured piece is replaced so quickly by the capturing piece that the removal of the captured piece was never detected. As a result, a presence-only recording device cannot specify exactly which piece was captured. The present invention was developed to provide a method by which the ambiguities encountered by presence-only devices can be resolved, so that the cost and convenience advantages of such devices can, thereby, be fully realized.
3. Comparison of Prior Art to the Present Invention
Prior art includes a number of presence-only devices that can record the moves of board games such as checkers and chess. Many such devices were created to play one side of a game against a human opponent, and are offered for sale by companies such as Fidelity Electronics, Novag and Saitek.
Prior art presence-only devices use a number of methods for resolving the ambiguities mentioned above when determining which moves have been made by their human opponents. Some devices use pressure sensitive switches under each board square (U.S. Pat. No. 2,434,066). The human player is required to press down on a piece before it is moved, and then to press down on the piece once again after it is placed on the destination square. Specific examples are the Novag Obsidian, the Saitek Mephisto and a device commonly marketed as the USB Roll-up Chess Board.
Still other presence-only devices require that a permanent magnet be placed into the base of each playing piece. The resulting magnetic field is then detected by sensors placed at each playing location (U.S. Pat. Nos. 3,843,132 & 4,981,300, U.K. Patent GB-2,051,589 & German Patent DE-2,932,167). However, to resolve the aforementioned ambiguities, these devices require the user to execute moves in a strict sequence. A capture move in chess, for example, may require that the captured piece be lifted first, followed by the lifting of the capturing piece, followed by the placement of the capturing piece on the square of the captured piece. An example of a device that requires such sequences is the Novag Citrine.
All of the aforementioned prior art suffers from the primary disadvantage of inconvenience to the human players. Pressing switches and executing strict move sequences is unnatural for many players and distracts them from the game. The method of the present invention improves upon the prior art by using sophisticated post-processing of move information in order to resolve move ambiguities. The human players are, thereby, freed from the requirement to follow strict manual move protocols and can make moves in their individual and varied fashions.